Sharepoint 2013 blank values in Taxonomy Fields

When Taxonomy Fields are used in a site collection, a hidden list is created by SharePoint to save the terms that are tagged in that Site Collections. You can access the taxonomy hidden list from URL:-

{SiteCollection}}/Lists/TaxonomyHiddenList/AllItems.aspx

There is a Timer job called "Taxonomy Update Scheduler" that does the update Operation on TaxonomyHiddenList on an hourly basis with updated value from managed meta data services.

By default TaxonomyHidden list is having read permission to "Authenticated Users". But if you remove permission of "Authenticated Users" from site then it will also remove their permissions from this taxonomy hidden list. Due to this when non administrator user browse to list then he/she we see blank values in the managed meta data columns.  For more information on this issue you can browse to this article

To resolve this issue you need to give grant permission to the TaxonomyHiddenList. Now this can be done manually or through powershell. Following is the powershell solution which iterate through all the site collection and give read permission to owner, members and visitors on the TaxonomyHiddenList:-